Add Lua bitop library (#9847)

minetest · Nov 26, 2021 · b905138 · b905138
1 parent 7a1464d
commit b905138
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diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -261,6 +261,11 @@ endif()
 find_package(GMP REQUIRED)
 find_package(Json REQUIRED)
 find_package(Lua REQUIRED)
+if(NOT USE_LUAJIT)
+	set(LUA_BIT_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/lib/bitop)
+	set(LUA_BIT_LIBRARY bitop)
+	add_subdirectory(lib/bitop)
+endif()
 
 # JsonCpp doesn't compile well on GCC 4.8
 if(NOT USE_SYSTEM_JSONCPP)

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
@@ -8825,3 +8825,10 @@ Used by `minetest.register_authentication_handler`.
         -- Returns an iterator (use with `for` loops) for all player names
         -- currently in the auth database
     }
+
+Bit Library
+-----------
+
+Functions: bit.tobit, bit.tohex, bit.bnot, bit.band, bit.bor, bit.bxor, bit.lshift, bit.rshift, bit.arshift, bit.rol, bit.ror, bit.bswap
+
+See http://bitop.luajit.org/ for advanced information.
diff --git a/lib/bitop/CMakeLists.txt b/lib/bitop/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_library(bitop bit.c)
+target_link_libraries(bitop)
+
+include_directories(${LUA_INCLUDE_DIR})
diff --git a/lib/bitop/bit.c b/lib/bitop/bit.c
@@ -0,0 +1,189 @@
+/*
+** Lua BitOp -- a bit operations library for Lua 5.1/5.2.
+** http://bitop.luajit.org/
+**
+** Copyright (C) 2008-2012 Mike Pall. All rights reserved.
+**
+** Permission is hereby granted, free of charge, to any person obtaining
+** a copy of this software and associated documentation files (the
+** "Software"), to deal in the Software without restriction, including
+** without limitation the rights to use, copy, modify, merge, publish,
+** distribute, sublicense, and/or sell copies of the Software, and to
+** permit persons to whom the Software is furnished to do so, subject to
+** the following conditions:
+**
+** The above copyright notice and this permission notice shall be
+** included in all copies or substantial portions of the Software.
+**
+** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+** SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**
+** [ MIT license: http://www.opensource.org/licenses/mit-license.php ]
+*/
+
+#include "bit.h"
+
+#define LUA_BITOP_VERSION	"1.0.2"
+
+#define LUA_LIB
+#include "lauxlib.h"
+
+#ifdef _MSC_VER
+/* MSVC is stuck in the last century and doesn't have C99's stdint.h. */
+typedef __int32 int32_t;
+typedef unsigned __int32 uint32_t;
+typedef unsigned __int64 uint64_t;
+#else
+#include <stdint.h>
+#endif
+
+typedef int32_t SBits;
+typedef uint32_t UBits;
+
+typedef union {
+  lua_Number n;
+#ifdef LUA_NUMBER_DOUBLE
+  uint64_t b;
+#else
+  UBits b;
+#endif
+} BitNum;
+
+/* Convert argument to bit type. */
+static UBits barg(lua_State *L, int idx)
+{
+  BitNum bn;
+  UBits b;
+#if LUA_VERSION_NUM < 502
+  bn.n = lua_tonumber(L, idx);
+#else
+  bn.n = luaL_checknumber(L, idx);
+#endif
+#if defined(LUA_NUMBER_DOUBLE)
+  bn.n += 6755399441055744.0;  /* 2^52+2^51 */
+#ifdef SWAPPED_DOUBLE
+  b = (UBits)(bn.b >> 32);
+#else
+  b = (UBits)bn.b;
+#endif
+#elif defined(LUA_NUMBER_INT) || defined(LUA_NUMBER_LONG) || \
+      defined(LUA_NUMBER_LONGLONG) || defined(LUA_NUMBER_LONG_LONG) || \
+      defined(LUA_NUMBER_LLONG)
+  if (sizeof(UBits) == sizeof(lua_Number))
+    b = bn.b;
+  else
+    b = (UBits)(SBits)bn.n;
+#elif defined(LUA_NUMBER_FLOAT)
+#error "A 'float' lua_Number type is incompatible with this library"
+#else
+#error "Unknown number type, check LUA_NUMBER_* in luaconf.h"
+#endif
+#if LUA_VERSION_NUM < 502
+  if (b == 0 && !lua_isnumber(L, idx)) {
+    luaL_typerror(L, idx, "number");
+  }
+#endif
+  return b;
+}
+
+/* Return bit type. */
+#define BRET(b)  lua_pushnumber(L, (lua_Number)(SBits)(b)); return 1;
+
+static int bit_tobit(lua_State *L) { BRET(barg(L, 1)) }
+static int bit_bnot(lua_State *L) { BRET(~barg(L, 1)) }
+
+#define BIT_OP(func, opr) \
+  static int func(lua_State *L) { int i; UBits b = barg(L, 1); \
+    for (i = lua_gettop(L); i > 1; i--) b opr barg(L, i); BRET(b) }
+BIT_OP(bit_band, &=)
+BIT_OP(bit_bor, |=)
+BIT_OP(bit_bxor, ^=)
+
+#define bshl(b, n)  (b << n)
+#define bshr(b, n)  (b >> n)
+#define bsar(b, n)  ((SBits)b >> n)
+#define brol(b, n)  ((b << n) | (b >> (32-n)))
+#define bror(b, n)  ((b << (32-n)) | (b >> n))
+#define BIT_SH(func, fn) \
+  static int func(lua_State *L) { \
+    UBits b = barg(L, 1); UBits n = barg(L, 2) & 31; BRET(fn(b, n)) }
+BIT_SH(bit_lshift, bshl)
+BIT_SH(bit_rshift, bshr)
+BIT_SH(bit_arshift, bsar)
+BIT_SH(bit_rol, brol)
+BIT_SH(bit_ror, bror)
+
+static int bit_bswap(lua_State *L)
+{
+  UBits b = barg(L, 1);
+  b = (b >> 24) | ((b >> 8) & 0xff00) | ((b & 0xff00) << 8) | (b << 24);
+  BRET(b)
+}
+
+static int bit_tohex(lua_State *L)
+{
+  UBits b = barg(L, 1);
+  SBits n = lua_isnone(L, 2) ? 8 : (SBits)barg(L, 2);
+  const char *hexdigits = "0123456789abcdef";
+  char buf[8];
+  int i;
+  if (n < 0) { n = -n; hexdigits = "0123456789ABCDEF"; }
+  if (n > 8) n = 8;
+  for (i = (int)n; --i >= 0; ) { buf[i] = hexdigits[b & 15]; b >>= 4; }
+  lua_pushlstring(L, buf, (size_t)n);
+  return 1;
+}
+
+static const struct luaL_Reg bit_funcs[] = {
+  { "tobit",	bit_tobit },
+  { "bnot",	bit_bnot },
+  { "band",	bit_band },
+  { "bor",	bit_bor },
+  { "bxor",	bit_bxor },
+  { "lshift",	bit_lshift },
+  { "rshift",	bit_rshift },
+  { "arshift",	bit_arshift },
+  { "rol",	bit_rol },
+  { "ror",	bit_ror },
+  { "bswap",	bit_bswap },
+  { "tohex",	bit_tohex },
+  { NULL, NULL }
+};
+
+/* Signed right-shifts are implementation-defined per C89/C99.
+** But the de facto standard are arithmetic right-shifts on two's
+** complement CPUs. This behaviour is required here, so test for it.
+*/
+#define BAD_SAR		(bsar(-8, 2) != (SBits)-2)
+
+LUALIB_API int luaopen_bit(lua_State *L)
+{
+  UBits b;
+  lua_pushnumber(L, (lua_Number)1437217655L);
+  b = barg(L, -1);
+  if (b != (UBits)1437217655L || BAD_SAR) {  /* Perform a simple self-test. */
+    const char *msg = "compiled with incompatible luaconf.h";
+#ifdef LUA_NUMBER_DOUBLE
+#ifdef _WIN32
+    if (b == (UBits)1610612736L)
+      msg = "use D3DCREATE_FPU_PRESERVE with DirectX";
+#endif
+    if (b == (UBits)1127743488L)
+      msg = "not compiled with SWAPPED_DOUBLE";
+#endif
+    if (BAD_SAR)
+      msg = "arithmetic right-shift broken";
+    luaL_error(L, "bit library self-test failed (%s)", msg);
+  }
+#if LUA_VERSION_NUM < 502
+  luaL_register(L, "bit", bit_funcs);
+#else
+  luaL_newlib(L, bit_funcs);
+#endif
+  return 1;
+}
diff --git a/lib/bitop/bit.h b/lib/bitop/bit.h
@@ -0,0 +1,34 @@
+/*
+** Lua BitOp -- a bit operations library for Lua 5.1/5.2.
+** http://bitop.luajit.org/
+**
+** Copyright (C) 2008-2012 Mike Pall. All rights reserved.
+**
+** Permission is hereby granted, free of charge, to any person obtaining
+** a copy of this software and associated documentation files (the
+** "Software"), to deal in the Software without restriction, including
+** without limitation the rights to use, copy, modify, merge, publish,
+** distribute, sublicense, and/or sell copies of the Software, and to
+** permit persons to whom the Software is furnished to do so, subject to
+** the following conditions:
+**
+** The above copyright notice and this permission notice shall be
+** included in all copies or substantial portions of the Software.
+**
+** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+** SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**
+** [ MIT license: http://www.opensource.org/licenses/mit-license.php ]
+*/
+
+#pragma once
+
+#include "lua.h"
+
+#define LUA_BITLIBNAME "bit"
+LUALIB_API int luaopen_bit(lua_State *L);
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
@@ -500,6 +500,7 @@ include_directories(
 	${LUA_INCLUDE_DIR}
 	${GMP_INCLUDE_DIR}
 	${JSON_INCLUDE_DIR}
+	${LUA_BIT_INCLUDE_DIR}
 	${X11_INCLUDE_DIR}
 	${PROJECT_SOURCE_DIR}/script
 )
@@ -537,6 +538,7 @@ if(BUILD_CLIENT)
 		${LUA_LIBRARY}
 		${GMP_LIBRARY}
 		${JSON_LIBRARY}
+		${LUA_BIT_LIBRARY}
 		${PLATFORM_LIBS}
 	)
 	if(NOT USE_LUAJIT)
@@ -619,6 +621,7 @@ if(BUILD_SERVER)
 		${SQLITE3_LIBRARY}
 		${JSON_LIBRARY}
 		${LUA_LIBRARY}
+		${LUA_BIT_LIBRARY}
 		${GMP_LIBRARY}
 		${PLATFORM_LIBS}
 	)

diff --git a/src/script/cpp_api/s_base.cpp b/src/script/cpp_api/s_base.cpp
@@ -37,6 +37,8 @@ extern "C" {
 #include "lualib.h"
 #if USE_LUAJIT
 	#include "luajit.h"
+#else
+	#include "bit.h"
 #endif
 }
 
@@ -88,6 +90,11 @@ ScriptApiBase::ScriptApiBase(ScriptingType type):
 	else
 		luaL_openlibs(m_luastack);
 
+	// Load bit library
+	lua_pushcfunction(m_luastack, luaopen_bit);
+	lua_pushstring(m_luastack, LUA_BITLIBNAME);
+	lua_call(m_luastack, 1, 0);
+
 	// Make the ScriptApiBase* accessible to ModApiBase
 #if INDIRECT_SCRIPTAPI_RIDX
 	*(void **)(lua_newuserdata(m_luastack, sizeof(void *))) = this;

diff --git a/src/script/cpp_api/s_security.cpp b/src/script/cpp_api/s_security.cpp
@@ -106,6 +106,7 @@ void ScriptApiSecurity::initializeSecurity()
 		"string",
 		"table",
 		"math",
+		"bit"
 	};
 	static const char *io_whitelist[] = {
 		"close",
@@ -298,6 +299,7 @@ void ScriptApiSecurity::initializeSecurityClient()
 		"string",
 		"table",
 		"math",
+		"bit",
 	};
 	static const char *os_whitelist[] = {
 		"clock",
@@ -834,4 +836,3 @@ int ScriptApiSecurity::sl_os_remove(lua_State *L)
 	lua_call(L, 1, 2);
 	return 2;
 }
-